Automatic merge from submit-queue (batch tested with PRs 60302, 57921, 59042, 60126, 59561). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Allow to specify categories for custom resources

Allow to specify categories for custom resources so that we can get it working with `kubectl get all`. 

Adds a new field `Categories` in the CRD spec.

**Release note**:

```release-note
Custom resources can be listed with a set of grouped resources (category) by specifying the categories in the CustomResourceDefinition spec. Example: They can be used with `kubectl get all`, where `all` is a category.
```

/cc sttts liggitt deads2k